The size of wheel limits the application of a carrier. In the prior art, wheels have different sizes in diameter to be used in different fields, for instance, wheelchairs or carts are suitable for small sized wheels. In these devices, the wheels are attached to a wheel frame in connection to the seat and seat frame for energy saving and mass delivery. Since the wheels attached to bottom of frame, the apparent size of the carrier is enlarged and perturbed when placed in the trunk.